While looking at reusing partitions via partman I noticed we have quite a bit of too-specific configurations. For hosts with standard recipes we know we want to format vg0/root filesystem and keep everything else, therefore there should be a single configuration/recipe for folks to include that does exactly that.

For example it should be as easy as this:

Non reuse case:

'cumin*|parsoidtest1001':
  - partman/standard.cfg
  - partman/raid1-2dev.cfg

Reuse case

'cumin*|parsoidtest1001':
  - partman/standard.cfg
  - partman/raid1-2dev.cfg
  - partman/reuse.cfg

Note that the implementation will likely require to extend/adapt reuse-parts.sh to make it aware of standard recipes layout, or write something different based on it. Local testing can be achieved with https://gitlab.wikimedia.org/repos/sre/preseed-test